Lock for railway spring switches



Jam. 14, 136. P. RENSHAW LOCK FOR RAILWAY SPRING SWITCHES Filed July 14, 1934 2 Sheets-Sheet l Jan 14;, 1936. P HA zmz'mz LOCK FOR. RAILWAY SPRING SWITCHES Filed July 14, 1934 2 Sheets-Sheet 2 Fma;

r H 0-0. P a c r INVENTOR Patented Jan. 14, 1936 UNITED STATES PATENT ()FFICE Paul Renshaw, New York, N. Y.,. assignor to General Railway Signal Company, Rochester,

Application July-14, 1934, Serial No. 735,246

9 Claims.

This invention relates to looks for spring switches on railroads, and more'particularly to a plunger type lock normally effective to lock the switch points for a facing point move and automatically released by the wheels of a train trailing through the switch.

In applying the well known spring switches to sidings and the like on railroads, it is desirable to provide a lock for firmly holding the switch points for trains moving in the facing point direction, so that the point may not be displaced by jar or vibration during the movement of train travelling at speed over the switch. Further provision may also be made to control the signal governing trafiic in the facing direction so that it can not clear unless the switch points are properly locked. With such a lock arrangement, provision must be made to permit the lock to be released for a train to trail through the switch. This may be accomplished by a manual device, such as disclosed, for example, in the patent to J. A. Peabody, No. 1,847,894 March 1, 1932.

In accordance with this invention it is proposed to provide a lock for spring switches which is automatically released mechanically by the wheels of a train approaching in the trailing direction; and it is also proposed to provide means by which the lock may be released and the switch points shifted by hand, together with contacts for controlling signals in accordance with the locked or unlocked condition of the switch.

The accompanying drawings illustrate in a 35. simplified and] diagrammatic manner specific embodiments of the invention, the parts being shown more with the view of illustrating the nature of the invention than the details of the structure and arrangement of parts that would be preferably employed in practice.

In these drawings, Fig. 1 is a general plan view;

Figs. 2 and 3 are fragmentary vertical sections,

on lines 2-2 and 3-3 in Fig. 1; and

45. Figs. 4 and 5 illustrate a modification or variation in the structure of the wheel actuated treadle.

The invention contemplates a spring switch of the usual type and construction, in which the switch points I are urged to one position, the normal position as shown, by a spring 2, with a dash-pot device 3 for retarding the movement of the points, in accordance with the usual practice. A lock rod LR is adjustably connected to the usual front rod 4, and is guided and supported in a suitable base or supporting member 5 secured to the ties. A locking plunger LP is arranged to enter a notch in the lock rod LR in a manner characteristic of the usual plunger l2 and a cross rod I3 to a suitable wheel actuated treadle device T. This treadle device T is associated with one of the rails of the turnout track, and is located an appropriate distance from a switch point so that it is actuated by the wheels of an approaching car or locomotive before these wheels advance far enough along the switch points to exert much side pressure against the points.

One form of treadle structure is shown in Figs. 1 and 3, and comprises a bar I4 journalled on studs I5 fastened to the web of the rail, and connected by a suitable ball and socket connection I6 to the rod I3. The member I4 is positioned so that it is rocked or displaced by the flanges of the wheels to pull on the rod I3.

The treadle structure shown in Figs. 4 and 5 comprises a horizontal bar I1, supported on parallel rocker shafts i8, and connected by a ball and socket connection I6 to the rod I3. This treadle bar I! is shown as urged to the upper portion by springs I9; and the rocker arms I8 are connected by a link 20 and are formed with stops to limit the upper movement of said treadle bar. This treadle bar I! is preferably disposed on the inside of the track rail so as to be depressed by the wheel flanges, but it may be mounted along the outside of the track rail, and otherwise constructed and supported in a manner similar tothat employed for detector bars.

Under normal conditions, the switch points I are moved to the position shown by the spring 2, and the locking plunger LP locks the lock rod LR. In this locked condition of the switch, an adjustable contact actuating member 22 engages and closes contacts 23, which are included in a circuit controlling the clearing of a signal (not shown) governing the trafiic over the switch in the facing direction, from left to right.

It is sometimes necessary for a spring switch to be unlocked and moved by hand to the reverse position, as for example, when a train approaching the facing direction desires to take the turn-out track. For this purpose a hand lever 24 is attached to a shaft 25, to which is fixed a cam 26 (see Fig. 2) disposed under the locking plunger LP, so that preliminary movement of the hand lever 24 raises this locking plunger to disengage it from the lock rod LR, the spring 9 being compressed during this movement. This cam member 28 is also provided with a cam surface, as best shown in Fig. l, to cooperate with a cam member 2'! fixed to the rod connected to the switch points, so that after the preliminary movement of the hand lever 24 sufficient to unlock the points, further movement of this hand lever moves the points to the reverse position.

The switch points are urged to the normal position shown by the spring 2, and the lock is normally eiTective. Under these conditions the contacts 23 are closed, and the signal governing train movements over the switch in the facing direction may clear, and trains may pass over the switch at relatively high speeds, since the points are positively and definitely held in the normal position. In this connection, it should be understood that the parts are proportioned in accordance with the usual practice so that the locking plunger LP cannot engage the notch in the lock rod LR, unless the switch points are in thefull normal position.

A train approaching the switch from the side.

track or diverging route, and trailing over the switch points, operates the treadle T before reaching the points; and this pulls the locking plunger LP endwise to disengage the lock rod LR, at the same time opening the contacts 23. The switch points can then be forced over by the usual train in the usual way. The dash pot 3 retards the return movement of the switch points by the spring 2 between the trucks of the train; and in this connection the treadle T is preferably of such length and positioned at an appropriate distance from the ends of the switch points such that either points will be held over by the wheels, or the treadle will be held down, thereby preventing the switch points returning and becoming locked up under a standing train.

One important characteristic of this invention is that the switch lock is mechanically released by the wheels of the approaching train before any sidewise pressure is applied to the points to bind the lock.

The way in which the switch may be unlocked and moved by hand through the medium of the hand lever 24 will be evident.

The construction and arrangement of parts shown and described is merely illustrative; and various modifications, adaptations, and additions may be made in this construction, without departing from the invention. For example, locking plunger LP and associated parts are preferably closed and housed in a casing, althouglr shown for simplicity as open and exposed.

What I claim is:-

l. A locking device for spring switches comprising, a lock rod and a locking plunger, and a wheel actuated treadle device associated with; the track rails of the diverging track for releasing said plunger upon the approach of a train in the trailing direction.

.2. A locking device for spring switches comprising, a lock rod connected to the switch points, a locking plunger adapted to engage a notch on said lock rod, a wheel actuated treadle associated with a diverging track rail, and means mechanically connecting said treadle and locking plunger.

3. A switch lock comprising, a locking plunger movable lengthwise and transversely, wheel actuated treadle means moving said plunger longitudinally, and a hand lever means for moving said plunger transversely.

4. An automatically operated lock for spring switches comprising, a lock rod, a locking plunger cooperating therewith to hold the switch points in theirspring actuated position, wheel actuated treadle means disposed at a distance from the switch point for actuating said looking plunger to its unlocked position before moving the switch points, contacts, and means for closing the contacts only if said locking plunger is in its locking position.

5. A lock for spring switches comprising, a locking plunger, car wheel actuated means for releasing said plunger, and a hand-throw device having means for releasing said plunger and shifting the switch points.

6. A switch lock for spring switches comprising, a lock, means for mechanically releasing the lock by the wheels of a train approaching in the trailing direction, said means being positioned to be operated before said wheels exert pressure tending to move the switch points.

'7. A lock for spring switches comprising, a locking plunger, spring means urging said plunger to its locking position, a wheel actuated treadle positioned to be traversed by a train approaching the switch in a trailing direction, and means mechanically connecting said plunger and said treadle, whereby the lock is released mechanically by a train approaching the switch in the trailing direction.

.8. In a spring switch, a notched lock rod, a lock plunger receivable in the notch in the rod, a track treadle operator, 2, hand switch throw lever operator, a slide in which the plunger can slide, a pivot about which the plunger can rock, and means whereby the operators can slide and rock the plunger, into and out of, engagement with its lock rod.

9. In a spring switch, a notched lock rod, a lock plunger receivable in the notch in the rod, a track treadle, a hand switch throw lever, a slide in which the plunger can slide, a pivot about which the plunger can rock, and means 

